This is a mount for circuit boards with a size of 56mm x 100mm which can be screwed or glued on a surface. Size can be easily adjusted as OpenSCAD file is attached. Heads of screws are countersunked, so they can't cause short circuits.
Prints without support with a layer height of 0.3mm on Prusa i3 Hephestos. Overhangs of 2mm aren't a problem on my printer.